BMW 803

This engine was designed for long-range bombers, but was still in the development stage at the end of the war. Only a few rare specimens ever ran on the test bench. The engine on display here is one of the few survivors. With a projected output of 4000 hp, is was one of the most powerful and heaviest engines of the time. (In contrast: the strongest piston engines after the war were the American built R-4360 and R-3350 with an output of 3500 hp). 

It soon became apparent that piston engines with this level of performance were too heavy and complex for use in airplanes. Further development of the piston engine came to a halt. The new priority was towards jet engines.

The special feature of this engine is its design as a double engine. Two engines positioned in a row, but running independently of one another, powered two contraprops. In air-cooled, several-rowed radial engines it is difficult to supply the rear cylinders with cooling air. The liquid cooling system seen here is unusual for radial engines and cools the four cylinder banks.

• Manufacturer: BMW-Flugmotorenbau GmbH, Berlin-Spandau, 1944
• 28-cylinder double engine composed of two independent 14-cylinder two-bank radial engines, liquid-cooled. Power transmission from the rear engine to the propeller via five torsion shafts. Four-stroke engine, two two-stage superchargers, fuel injection.
• Take-off power: 2940 kW (4000 hp)
• Speed: 2950 rpm
• Fuel consumption: 380 g/kWh
• Cubic capacity: 85.5 l
• Bore diameter:156 mm
• Stroke: 56 mm
• Mass:4130 kg